Mountcastle, 19, is batting .405 with three home runs and seven RBI over the last 10 games for Low-A Delmarva.
The recent surge by Mountcastle, a first round pick in 2015, pushes his overall slash line to .290/.364/.443. He is only scratching the surface of his potential, as he is expected to have decent power for a shortstop, assuming he stays at that position. He has also swiped three bases in 41 games at this level.